This proposal is designed as a multi-disciplinary approach to the study of neurotransmitter systems in the retina. The overall goal of this project is to a) identify the functional neurotransmitters in the retina, b) determine the cellular and subcellular localization of specific neurotransmitter systems, and c) elucidate possible control mechanisms for chemical transmission in retina. Biochemical techniques have been developed by the principal investigator for qualitation and quantitation of neurotransmitter substances released from neuronal preparations. The co-investigator has developed techniques for localization and quantitation of specific neurotransmitter substances at the EM level. The success of these biochemical and microscopic techniques in brain preparations, and results of preliminary retina studies, leave little doubt as to the potential usefulness of these techniques in retina. The proposed biochemical and microscopic studies will be correlated with a collaborative electrophysiological study of retina. The focus of these three areas of expertise on retinal transmitters will produce integrated information about chemical transmission as it functions in visual processing in retina.